Helminth Infection Status Research Articles

Interplay Between Helminth Infections, Malnutrition, and Gut Microbiota in Children and Mothers from Pemba, Tanzania: Potential of Microbiota-Directed Interventions.

Despite efforts within the framework of the Sustainable Development Goal to end malnutrition by 2030, malnutrition and soil-transmitted helminth infections persist in sub-Saharan Africa. A significant barrier to success is the inadequate understanding of effective intervention methods. Most research on the gut microbiota's role in health has been conducted in developed countries, leaving a critical gap in knowledge regarding low-income populations. This study addresses this gap by expanding research on the gut microbiota of underprivileged populations to help tackle these public health challenges. We employed 16S rDNA sequencing to assess the bacterial gut microbiota composition of 60 children (mean age: 26.63 ± 6.36 months) and their 58 mothers (mean age: 30.03 ± 6.31 years) in Pemba, with a focus on helminth infection and nutritional status. Our differential abundance analysis identified bacterial taxa that were significantly negatively associated with both helminth infections and malnutrition, highlighting the potential for microbiota-directed interventions to address these health issues simultaneously. Notably, we identified Akkermansia, Blautia, Dorea, and Odoribacter as promising probiotic candidates for such interventions. In stunted children, positive co-occurrences were observed between Lactobacillus, Prevotella, and Bacteroides, while Escherichia/Shigella displayed negative co-abundance relationships with short-chain fatty acid (SCFA) producers in the gut microbiota. These findings suggest that administering Lactobacillus and SCFA-producing probiotics to children may foster the growth of beneficial bacteria like Prevotella and Bacteroides while reducing the relative abundance of Escherichia/Shigella, potentially enhancing overall health. This study underscores the importance of microbiota-directed interventions in children and women of reproductive age as promising strategies, alongside established approaches, for combating helminth infections and malnutrition in vulnerable populations.

Intestinal Helminth Infections and Their Association with QuantiFERON-TB Gold Plus Test Performance in an Endemic Setting, Northwest Ethiopia.

Timely detection and treatment of latent TB infection (LTBI) is part of WHO's strategy against tuberculosis (TB). Helminth infections can modulate immune responses, potentially impacting the performance of interferon-gamma release assays (IGRAs) such as the QuantiFERON-TB Gold Plus (QFT-Plus). This study evaluated the association between helminth infections and QFT-Plus results among participants from a TB-endemic region. A cross-sectional study was conducted from October 2022 to March 2023 in Bahir Dar, Ethiopia. Stool samples of 314 potential participants were examined for helminths using wet mount and Kato-Katz techniques. LTBI was assessed by QFT-Plus from a total of 100 gender-matched helminth-positive and -negative participants. The association between helminth infection status, egg count, and QFT-Plus positivity was analyzed, and p values <0.05 were considered significant. Overall, 53 of 314 screened participants were infected with helminths (16.9%), with A. lumbricoides (47.2%) and hookworm (30.2%) as most prevalent species. The overall QFT-Plus positivity rate was 30.0%, with similar rates observed between helminth-positive and helminth-negative participants. Although QFT-Plus positivity was slightly lower in hookworm carriers (25%) compared to those with A. lumbricoides (32%), a higher-than-median hookworm egg burden was significantly associated with reduced QFT-Plus positivity (P = 0.029). QFT-Plus positivity was significantly higher among male participants than females (P = 0.032). While overall helminth infection status did not significantly affect QFT-Plus positivity, higher hookworm burden was associated with reduced QFT-Plus reactivity. These findings suggest that the type of helminth and infection intensity, rather than its mere presence, may influence IGRA performance. Further studies with larger sample sizes are warranted to understand the species-specific effect of helminth infection on immune modulation of the host.

Intestinal Helminth Infection Impairs Oral and Parenteral Vaccine Efficacy.

The impact of endemic parasitic infection on vaccine efficacy is an important consideration for vaccine development and deployment. We have examined whether intestinal infection with the natural murine helminth Heligmosomoides polygyrus bakeri alters Ag-specific Ab and cellular immune responses to oral and parenteral vaccination in mice. Oral vaccination of mice with a clinically relevant, live, attenuated, recombinant Salmonella vaccine expressing chicken egg OVA (Salmonella-OVA) induced the accumulation of activated, OVA-specific T effector cells rather than OVA-specific regulatory T cells in the GALT. Intestinal helminth infection significantly reduced Th1-skewed Ab responses to oral vaccination with Salmonella-OVA. Activated, adoptively transferred, OVA-specific CD4+ T cells accumulated in draining mesenteric lymph nodes of vaccinated mice, regardless of their helminth infection status. However, helminth infection increased the frequencies of adoptively transferred OVA-specific CD4+ T cells producing IL-4 and IL-10 in the mesenteric lymph node. Ab responses to the oral Salmonella-OVA vaccine were reduced in helminth-free mice adoptively transferred with OVA-specific CD4+ T cells harvested from mice with intestinal helminth infection. Intestinal helminth infection also significantly reduced Th2-skewed Ab responses to parenteral vaccination with OVA adsorbed to alum. These findings suggest that vaccine-specific CD4+ T cells induced in the context of helminth infection retain durable immunomodulatory properties and may promote blunted Ab responses to vaccination. They also underscore the potential need to treat parasitic infection before mass vaccination campaigns in helminth-endemic areas.

Hubungan Infeksi Soil Transmitted Helminth dengan Status Gizi Balita di Desa Tesabela, Kabupaten Kupang, Nusa Tenggara Timur

Helminthiasis infection is one of the diseases that still occurs in the surrounding community. One type of helminthiasis disease that results in infection is the STH worm. Nutritional status problems are commonly encountered in various provinces of Indonesia which results in the quality of oneself for the future will be affected. The purpose of this study was to determine the relationship between helminthiasis infections and nutritional status in toddlers based on anthropometric measurements using weight and height indices. The type of research used is descriptive with a Cross sectional research design. Data that has been collected from 62 patients was described to link STH infection with Nutritional Status in Toddlers. The results of the study stated that there was no relationship between Soil Transmitted Helminth infection and gisi status in toddlers in Tesabela Village, West Kupang District with chis-quare test results, obtained a value of P=0.953 (P&gt;a0.05).

Gut microbiome of helminth-infected indigenous Malaysians is context dependent

BackgroundWhile microbiomes in industrialized societies are well characterized, indigenous populations with traditional lifestyles have microbiomes that are more akin to those of ancient humans. However, metagenomic data in these populations remains scarce, and the association with soil-transmitted helminth infection status is unclear. Here, we sequenced 650 metagenomes of indigenous Malaysians from five villages with different prevalence of helminth infections.ResultsIndividuals from villages with higher prevalences of helminth infections have more unmapped reads and greater microbial diversity. Microbial community diversity and composition were most strongly associated with different villages and the effects of helminth infection status on the microbiome varies by village. Longitudinal changes in the microbiome in response to albendazole anthelmintic treatment were observed in both helminth infected and uninfected individuals. Inference of bacterial population replication rates from origin of replication analysis identified specific replicating taxa associated with helminth infection.ConclusionsOur results indicate that helminth effects on the microbiota were highly dependent on context, and effects of albendazole on the microbiota can be confounding for the interpretation of deworming studies. Furthermore, a substantial quantity of the microbiome remains unannotated, and this large dataset from an indigenous population associated with helminth infections is a valuable resource for future studies.AEGeXaED_X6wKACk1ZMX_FVideo

Intestinal Helminth Infection, Anemia, Undernutrition and Academic Performance among School Children in Northwestern Ethiopia.

This study examined the prevalence and intensity of intestinal helminth infections and their association with anemia, undernutrition, and academic performance among school children in Maksegnit, northwestern Ethiopia. A total of 1205 school children, who attended Maksegnit Number Two Elementary School between May and July 2021, participated in this study. To determine helminth infection status, two thick Kato–Katz slides were examined for each child. Hemoglobin level was measured using a HemoCue machine. Academic performance was assessed using the mean score of all subjects children have taken for the Spring 2020/2021 academic term. Out of 1205 children examined, 45.4% were infected with at least one helminth species, 7.9% were anemic, and 35.8% were undernourished. The means for hemoglobin level and z-scores of weight for age, height for age, body mass index for age, and academic scores were lower among helminth-infected children than the uninfected. Children infected with intestinal helminths showed higher odds of anemia than those uninfected with helminths. In conclusion, there was a moderate prevalence of intestinal helminth infection and undernutrition among school children in Maksegnit. Intestinal helminth infection could increase the risk of anemia, undernutrition, and poor academic performance.

Exploring biocultural determinants of intestinal health: Do resource access and parasite exposure contribute to intestinal inflammation among a preliminary sample of children in rural Mississippi?

AbstractObjectivesBiocultural perspectives combining methods and theories from biological and cultural anthropology are needed to better understand socioeconomic and race‐based health inequities in the United States. For example, the developmental trajectories of gastrointestinal health disparities based on embodied (i.e., internalized) inequities in resource access and environmental pathogen exposure are poorly understood. Here, we present a preliminary exploration of these relationships among 20 children (aged 3–14 years) from 12 families living in a low‐resource, predominantly Black, rural Mississippi community.MethodsRelationships between fecal calprotectin levels (FC; biomarker of intestinal inflammation measured from stool samples), BMI‐for‐age/Height‐for‐age z‐scores (calculated from standard anthropometric measures), household income/size (from parent interviews), and parasitic worm (helminth) infection status (detected in stool samples by 18 s rRNA gene amplification/sequencing) were tested using bootstrap linear regression and ANOVA/ANCOVA tests.ResultsAbout 80% of sampled children had clinically elevated FC (&gt; 50 μg/g). BMI z‐scores (95%CI = −154.63; −7.34) and household income (95%CI = −135.90; −16.44) were negatively associated with FC levels. Household size was positively associated with FC levels (95%CI = 4.65, 101.61). Helminth infections were detected (n = 6), with positive associations between infection and the FC level (p &lt; 0.05) that were likely driven by two infected children with very high FC levels.ConclusionThe high levels of intestinal inflammation in this small sample of children suggest that gastrointestinal health disparities may appear in childhood. We explore how these disparities may be related to inequities in environmental exposures, nutritional and socioeconomic status, and barriers to medical care and resource access.

Anemia Etiology in Ethiopia: Assessment of Nutritional, Infectious Disease, and Other Risk Factors in a Population-Based Cross-Sectional Survey of Women, Men, and Children

BackgroundWhile the causes of anemia at an individual level (such as certain nutritional deficiencies, infections, and genetic disorders) are well defined, there is limited understanding of the relative burden of anemia attributable to each cause within populations. ObjectivesWe sought to estimate the proportion of anemia cases attributable to nutrition, infectious diseases, and other risk factors among women, men, and children in 6 regions of Ethiopia. MethodsA population-based cross-sectional study was conducted. Data were obtained from 2520 women of reproductive age (15–49 y), 1044 adult men (15–49 y), and 1528 children (6–59 mo). Participants provided venous blood samples for assessment of their hemoglobin concentration; ferritin, folate, vitamin B12, and C-reactive protein levels; and the presence of malaria infection. Stool samples were collected to ascertain the helminth infection status. Sociodemographic questionnaires and a 24-h diet recall were administered. Population-weighted prevalences of anemia and risk factors were calculated. Multivariable-adjusted associations of risk factors with anemia and partial population attributable risk percentages were estimated using generalized linear models. ResultsThe anemia prevalences were 17% (95% CI: 13%–21%) among women, 8% (95% CI: 6%–12%) among men, and 22% (95% CI: 19%–26%) among children. Low serum ferritin contributed to 11% (95% CI: −1% to 23%) of anemia cases among women, 9% (95% CI: 0%–17%) among men, and 21% (95% CI: 4%–34%) among children. The proportions of anemia attributable to low serum folate were estimated at 25% (95% CI: 5%–41%) among women and 29% (95% CI: 11%–43%) among men. Dietary iron intake was adequate for nearly all participants, while inadequacy was common for folate and vitamin B12. Inflammation and malaria were responsible for less than 1 in 10 anemia cases. ConclusionsFolate deficiency, iron deficiency, and inflammation appear to be important contributors to anemia in Ethiopia. Folic acid food fortification, targeted iron interventions, and strategies to reduce infections may be considered as potential public health interventions to reduce anemia in Ethiopia.

Association of soybean-based food with the prevalence of anaemia among reproductive-aged men and women in rural Central Java, Indonesia.

To assess the association between soybean consumption and anaemic status in Central Java, Indonesia. As part of an overarching sanitation improvement intervention in Central Java, Indonesia, we conducted a cross-sectional study in four rural villages. The study consisted of a 24-h food recall, anthropometric measurements, blood Hb measurement and stool sampling to test for soil-transmitted helminth (STH) infection status. A binary logistic regression model was fitted to test the association between soybean consumption and anaemic status after adjusting for socio-demographic factors, STH infection, dietary diversity and anthropometric status. This study took place in four rural villages of Wonosobo regency, Central Java, Indonesia. Participants were rural villagers aged between 15 and 49 years. A total sample size of 763 was attained, of which 231 were anaemic. The prevalence of anaemia was 30·2 % among men and women of reproductive age, and highest among young males. Consumption of soybean was high (79·8 %). After adjusting for covariates, the protective association between soybean consumption and anaemia was statistically significant (AOR = 0·53, 95 % CI = 0·30, 0·95, P < 0·05). There was a positive association with anaemia among underweight (AOR = 2·75, 95 % CI = 1·13, 6·69, P < 0·05) and those with high diet diversity (AOR = 1·40, 95 % CI = 1·00, 1·97, P < 0·05). Our results were consistent with studies from other countries finding a protective association between soybean consumption and anaemia. This association appeared stronger for tofu than for tempeh. The prevalence of anaemia in rural Central Java is relatively consistent with nation-wide statistics indicating that interventions targeting anaemia are still largely required.

Evidence of MHC class I and II influencing viral and helminth infection via the microbiome in a non-human primate.

Until recently, the study of major histocompability complex (MHC) mediated immunity has focused on the direct link between MHC diversity and susceptibility to parasite infection. However, MHC genes can also influence host health indirectly through the sculpting of the bacterial community that in turn shape immune responses. We investigated the links between MHC class I and II gene diversity gut microbiome diversity and micro- (adenovirus, AdV) and macro- (helminth) parasite infection probabilities in a wild population of non-human primates, mouse lemurs of Madagascar. This setup encompasses a plethora of underlying interactions between parasites, microbes and adaptive immunity in natural populations. Both MHC classes explained shifts in microbiome composition and the effect was driven by a few select microbial taxa. Among them were three taxa (Odoribacter, Campylobacter and Prevotellaceae-UCG-001) which were in turn linked to AdV and helminth infection status, correlative evidence of the indirect effect of the MHC via the microbiome. Our study provides support for the coupled role of MHC diversity and microbial flora as contributing factors of parasite infection.

Helminth infections and cardiovascular diseases: A role for the microbiota and Mϕs?

Cardiovascular diseases are rising in developing countries with increasing urbanization and lifestyle changes and remains a major cause of death in the developed world. In this mini review, we discuss the possibility that the effect of helminth infections on the immune system and the microbiota may affect risk factors in cardiovascular diseases such as atherosclerosis, as part of the hygiene hypothesis. The effects of Type 2 immune responses induced by helminths and helminth derived molecules on regulating metabolism and Mϕ function could be a mechanistic link for further investigation. We emphasize the complexity and difficulties in determining indirect or direct and causal relationships between helminth infection status and cardiovascular diseases. New experimental models, such as rewilding laboratory mice, whereby different aspects of the environment and host genetics can be carefully dissected may provide further mechanistic insights and therapeutic strategies for treating cardiovascular diseases.

The relationship between malnutrition and TH 2 immune markers: a study in school-aged children of different socio-economic backgrounds in Makassar, Indonesia.

ObjectiveThe burden of underweight remains a major problem in Indonesia, and at the same time, the prevalence of overweight is increasing. Malnutrition is a major determinant of health and has been linked to allergic disorders in children. We examined the relationship between malnutrition and TH2 immune markers in school‐aged children in Makassar, Indonesia.MethodsA cross‐sectional study was performed in five schools where socio‐demographic characteristics were recorded. Children’s standardised z‐scores of body mass index (z‐BMI) and age‐standardised z‐scores of height (z‐HA) were assessed using WHO child growth standards. Skin prick test (SPT) reactivity was determined to house dust mite allergens. Helminth infection status, (growth) hormones including insulin‐like growth factor (IGF‐1) and TH2 immune markers were measured.ResultsIn total, 954 children were included of whom 21.6% were underweight and 14.8% overweight. After controlling for confounders, overweight was positively associated with leptin (GMR 3.55, 95% CI: 2.99–4.23) and IGF‐1 (GMR 1.45, 95% CI: 1.15–1.82), whereas underweight was negatively associated (respectively GMR 0.57, 95% CI: 0.49–0.66 and GMR 0.78, 95% CI: 0.63–0.97). Underweight was associated with a lower eosinophil count (GMR 0.79, 95% CI: 0.64–0.97) but not with total IgE levels or SPT reactivity. Overweight was positively associated with SPT reactivity (adjusted OR 2.68, 95% CI: 1.50–4.78) but no relationship was found with the other TH2 immune markers.ConclusionMalnutrition is prominent in school‐aged children in Makassar, with overweight associated with increased SPT reactivity. Therefore, interventions should focus on undernutrition, but also on overweight to prevent the increase of allergic disorders in Indonesia.

Effect of anthelmintic treatment on serum free IGF-1 and IGFBP-3: a cluster-randomized-controlled trial in Indonesia

In children, soil-transmitted helminth infections have been linked to poor nutritional status and growth retardation in association with lower levels of IGF-1. In adults, IGF-1 has an anabolic and metabolic function and is related to nutritional status. Here, we assessed the impact of helminth infection on free IGF-1 and its major binding protein, IGFBP-3, in adults. The levels of IGF-1 and IGFBP3 were measured in 1669 subjects aged ≥ 16 years, before and after receiving four rounds of albendazole 400 mg/day or matching placebo for three consecutive days. Helminth infection status was assessed by microscopy (Kato-Katz) and PCR. Serum free IGF-1 level was significantly lower in helminth-infected subjects [mean difference and 95% CI − 0.068 (− 0.103; − 0.033), P < 0.001 after adjustment for age, sex, body mass index, and fasting insulin level]. There was no difference in IGFBP-3 level between helminth infected versus non-infected subjects. In the whole study population, albendazole treatment significantly increased serum free IGF-1 level [estimate and 95% CI 0.031 (0.004; − 0.057), P = 0.024] whereas no effect was found on the IGFBP-3 level. Our study showed that helminth infection in adults is associated with lower free IGF-1 levels but not with IGFBP-3 and albendazole treatment significantly increases free IGF-1 levels in the study population.Clinical Trial Registration: https://www.isrctn.com/ISRCTN75636394.

Schistosoma haematobium infection is associated with lower serum cholesterol levels and improved lipid profile in overweight/obese individuals.

Infection with parasitic helminths has been reported to improve insulin sensitivity and glucose homeostasis, lowering the risk for type 2 diabetes. However, little is known about its impact on whole-body lipid homeostasis, especially in obese individuals. For this purpose, a cross-sectional study was carried out in lean and overweight/obese adults residing in the Lambaréné region of Gabon, an area endemic for Schistosoma haematobium. Helminth infection status, peripheral blood immune cell counts, and serum metabolic and lipid/lipoprotein levels were analyzed. We found that urine S. haematobium egg-positive individuals exhibited lower serum total cholesterol (TC; 4.42 vs 4.01 mmol/L, adjusted mean difference [95%CI] -0.30 [-0.68,-0.06]; P = 0.109), high-density lipoprotein (HDL)-C (1.44 vs 1.12 mmol/L, -0.24 [-0.43,-0.06]; P = 0.009) and triglyceride (TG; 0.93 vs 0.72 mmol/L, -0.20 [-0.39,-0.03]; P = 0.022) levels than egg-negative individuals. However, when stratified according to body mass index, these effects were only observed in overweight/obese infected individuals. Similarly, significant negative correlations between the intensity of infection, assessed by serum circulating anodic antigen (CAA) concentrations, and TC (r = -0.555; P<0.001), HDL-C (r = -0.327; P = 0.068), LDL-C (r = -0.396; P = 0.025) and TG (r = -0.381; P = 0.032) levels were found in overweight/obese individuals but not in lean subjects. Quantitative lipidomic analysis showed that circulating levels of some lipid species associated with cholesterol-rich lipoprotein particles were also significantly reduced in overweight/obese infected individuals in an intensity-dependent manner. In conclusion, we reported that infection with S. haematobium is associated with improved lipid profile in overweight/obese individuals, a feature that might contribute reducing the risk of cardiometabolic diseases in such population.

Linking the effects of helminth infection, diet and the gut microbiota with human whole-blood signatures.

Helminth infection and dietary intake can affect the intestinal microbiota, as well as the immune system. Here we analyzed the relationship between fecal microbiota and blood profiles of indigenous Malaysians, referred to locally as Orang Asli, in comparison to urban participants from the capital city of Malaysia, Kuala Lumpur. We found that helminth infections had a larger effect on gut microbial composition than did dietary intake or blood profiles. Trichuris trichiura infection intensity also had the strongest association with blood transcriptional profiles. By characterizing paired longitudinal samples collected before and after deworming treatment, we determined that changes in serum zinc and iron levels among the Orang Asli were driven by changes in helminth infection status, independent of dietary metal intake. Serum zinc and iron levels were associated with changes in the abundance of several microbial taxa. Hence, there is considerable interplay between helminths, micronutrients and the microbiota on the regulation of immune responses in humans.

Infeksi nematode usus pada siswa Sekolah Dasar Negeri (SDN) Karang Mulyo 02, Kecamatan Pegandon, Kabupaten Kendal

The intestinal helminth infection was suffered mostly by pre-elementary and elementary students. This work was conducted to study the relationship between hygiene sanitation and intestinal helminth infection and the relationship between intestinal helminth infection and nutrition status in the students of SDN Karang Mulyo 02, Pegandon District, Kendal Regency. Survey method with a cross sectional approach was used in this study. The result showed that 21,57% of 51 subjects suffered intestinal helminth infection and the most common infection was a combination of Necator americanus and Ancylostoma duodenale infection. Hygiene sanitation of 74,51% respondens was good, however the nutrition status of the students was mostly bad according to weight to age as well as height to age, indicates i.e 56,87% out of 51 respondens. The energy and protein levels were less than standard and employing chi square analysis a positive correlation was found between hygiene sanitation and intestinal helminth infection but a negative correlation was found between intestinal helminth infection and nutrition status

The Effect of Gut Microbiome Composition on Human Immune Responses: An Exploration of Interference by Helminth Infections.

Background: Soil-transmitted helminths have been shown to have the immune regulatory capacity, which they use to enhance their long term survival within their host. As these parasites reside in the gastrointestinal tract, they might modulate the immune system through altering the gut bacterial composition. Although the relationships between helminth infections or the microbiome with the immune system have been studied separately, their combined interactions are largely unknown. In this study we aim to analyze the relationship between bacterial communities with cytokine response in the presence or absence of helminth infections. Results: For 66 subjects from a randomized placebo-controlled trial, stool and blood samples were available at both baseline and 21 months after starting three-monthly albendazole treatment. The stool samples were used to identify the helminth infection status and fecal microbiota composition, while whole blood samples were cultured to obtain cytokine responses to innate and adaptive stimuli. When subjects were free of helminth infection (helminth-negative), increasing proportions of Bacteroidetes was associated with lower levels of IL-10 response to LPS {estimate [95% confidence interval (CI)] −1.96 (−3.05, −0.87)}. This association was significantly diminished when subjects were helminth-infected (helminth positive) (p-value for the difference between helminth-negative versus helminth-positive was 0.002). Higher diversity was associated with greater IFN-γ responses to PHA in helminth-negative (0.95 (0.15, 1.75); versus helminth-positive [−0.07 (−0.88, 0.73), p-value = 0.056] subjects. Albendazole treatment showed no direct effect in the association between bacterial proportion and cytokine responses, although the Bacteroidetes’ effect on IL-10 responses to LPS tended downward in the albendazole-treated group [−1.74 (−4.08, 0.59)] versus placebo [−0.11 (−0.84, 0.62); p-value = 0.193]. Conclusion: We observed differences in the relationship between gut microbiome composition and immune responses, when comparing individuals infected or uninfected with geohelminths. Although these findings are part of a preliminary exploration, the data support the hypothesis that intestinal helminths may modulate immune responses, in unison with the gut microbiota. Trial Registration: ISRCTN, ISRCTN83830814. Registered 27 February 2008 — Retrospectively registered, http://www.isrctn.com/ISRCTN83830814.

Assessing longer-term effectiveness of a combined household-level piped water and sanitation intervention on child diarrhoea, acute respiratory infection, soil-transmitted helminth infection and nutritional status: a matched cohort study in rural Odisha, India.

BackgroundOpen defecation is widespread in rural India, and few households have piped water connections. While government and other efforts have increased toilet coverage in India, and evaluations found limited immediate impacts on health, longer-term effects have not been rigorously assessed.MethodsWe conducted a matched cohort study to assess the longer-term effectiveness of a combined household-level piped water and sanitation intervention implemented by Gram Vikas (an Indian NGO) in rural Odisha, India. Forty-five intervention villages were randomly selected from a list of those where implementation was previously completed at least 5 years before, and matched to 45 control villages. We conducted surveys and collected stool samples between June 2015 and October 2016 in households with a child <5 years of age (n = 2398). Health surveillance included diarrhoea (primary outcome), acute respiratory infection (ARI), soil-transmitted helminth infection, and anthropometry.ResultsIntervention villages had higher improved toilet coverage (85% vs 18%), and increased toilet use by adults (74% vs 13%) and child faeces disposal (35% vs 6%) compared with control villages. There was no intervention association with diarrhoea [adjusted OR (aOR): 0.94, 95% confidence interval (CI): 0.74–1.20] or ARI. Compared with controls, children in intervention villages had lower helminth infection (aOR: 0.44, 95% CI: 0.18, 1.00) and improved height-for-age z scores (HAZ) (+0.17, 95% CI: 0.03–0.31).ConclusionsThis combined intervention, where household water connections were contingent on community-wide household toilet construction, was associated with improved HAZ, and reduced soil-transmitted helminth (STH) infection, though not reduced diarrhoea or ARI. Further research should explore the mechanism through which these heterogenous effects on health may occur.

Are schoolchildren less infected if they have good knowledge about parasitic worms? A case study from rural C\xf4te d\u2019Ivoire

BackgroundParasitic worms (helminths) are common infections in low- and middle-income countries. For most helminth species, school-aged children are at highest risk of infection and morbidity, such as impaired cognitive and physical development. Preventive chemotherapy is the current mainstay for helminthiases control. Sanitation improvement and hygiene-related education are important complementary strategies, which act by altering children’s behaviour. However, little is known about the effect of improved knowledge on the risk of helminth infection. The aim of this study was to assess the potential influence of knowledge that children acquired at home or in school, without any specific health education intervention, on helminth infections.MethodsIn May 2014, we conducted a cross-sectional survey in western Côte d’Ivoire. A total of 2498 children, aged 9-12 years, were subjected to three consecutive stool examinations using duplicate Kato-Katz thick smears to determine infections with soil-transmitted helminths and Schistosoma mansoni. Additionally, children were interviewed to assess their knowledge about helminth infections. Four knowledge scores were constructed by factor analysis; one, reflecting general knowledge about helminths and three manifesting helminth species-specific knowledge. The effect of general and specific knowledge on children’s helminth infection status was determined using meta-analysis.ResultsChildren who scored high in the hookworm-specific knowledge were less likely to be infected with hookworm but no association was found for the other helminth species. Moreover, greater general knowledge was not associated with lower odds of being infected with any helminth species. Most of the children interviewed believed that the effect of preventive chemotherapy is permanent, and hence, re-treatment is not necessary.ConclusionsSpecific knowledge about different types of helminths might not suffice to induce behavioural change which in turn reduces infection and reinfection with helminths. Health education interventions should strive to strengthen the perception of risk and to clarify the true benefit of preventive chemotherapy.

Use of quantitative PCR to assess the efficacy of albendazole against Necator americanus and Ascaris spp. in Manufahi District, Timor-Leste

BackgroundSoil-transmitted helminths (STHs) including Ascaris lumbricoides, Necator americanus, Ancylostoma spp. and Trichuris trichiura are cause of significant global morbidity. To mitigate their disease burden, at-risk groups in endemic regions receive periodic mass drug administration using anthelmintics, most commonly albendazole and mebendazole. Assessing the efficacy of anthelmintic drugs is important for confirming that these regimens are working effectively and that drug resistance has not emerged. In this study we aimed to characterise the therapeutic efficacy of albendazole against Ascaris spp. and N. americanus in Timor-Leste, using a quantitative polymerase chain reaction (qPCR) method for parasite detection and quantification.ResultsA total of 314 participants from 8 communities in Timor-Leste provided stool samples before and 10–14 days after the administration of a single 400 mg dose of albendazole. Helminth infection status and infection intensity (measured in Ct-values and relative fluorescence units) were determined using qPCR. Efficacy was determined by examining the cure rates and infection intensity reduction rates. Albendazole was found to be highly efficacious against Ascaris spp., with a cure rate of 91.4% (95% CI: 85.9–95.2%) and infection intensity reduction rate of 95.6% (95% CI: 88.3–100%). The drug was less efficacious against N. americanus with a cure rate of 58.3% (95% CI: 51.4–64.9%) and infection intensity reduction rate of 88.9% (95% CI: 84.0–97.0%).ConclusionsThe observed cure rates and infection intensity reduction rates obtained for Ascaris spp. and to a lower extent N. americanus, demonstrate the continued efficacy of albendazole against these species and its utility as a mass chemotherapy agent in Timor-Leste. Furthermore, this study demonstrates the usefulness of qPCR as a method to measure the efficacy of anthelminthic drugs. Additional research is necessary to translate Ct-values into eggs per gram in a systematic way.Trial registrationAustralian and New Zealand Clinical Trials Registry 12614000680662 (registered 27 June 2014).